Homogenization of liquid matter



Patented Feb. 3, 1942 2,271,982 7 HOMOGENIZATION F LIQUID MATTER Arnold van Krcveld, Leeuwarden, Netherlands, assignor to'Coop. Condensfabriek Friesland, Leeuwarden, Netherlands Application March 6, 1939, SerlalNo. 259,980 In the Netherlands March 11; 1938 3 Claims. (01.99-265) This invention relates to means for homogeniz- 1 ing liquids and mixtures containing liquid matter.

It is an object, of this invention to provide means whereby homogenization can be effected in a more eflicacious and more economical manner than was hitherto possible,

As is well known to those skilled in the art, the homoginezing of liquid matter and liquidwmixtures forms an important step me. great number of industrial processes. Thus for instance the homogenization of milk and milk products serv ing to increase the dispersion of the fat particles in order to avoid fat separation is carried out on a great scale. This operation is particularly useful if applied to products which shall be preservedand stored for a long time.

While many different. types of homogenizing apparatus have been suggested, all of them have certain features in common. As a rulethe liquid is forced by means of a'pump through-'a valve consisting of difierent relatively movable parts.

In this valve theliquid is forced to pass through a very narrow and comparatively, long gap of variable width. In a well known type of homogenizer a cone is pressed by a powerful spring against its seat so as to altogether close the pas-,

sage. The liquid is forced to pass through between the cone and its seat, the pressure counteracting the passage of the liquid being regulated by increasing or reducing the spring pressure. The extent of pressure determining the intensity of homogenization or emulsification is measured by means of a manometer (pressure gauge) arranged upstream of the cone.

In another homogenizing apparatus the liquid is forced through a capillary or a bundle of capillaries, which are closed by a resilient plate. In a third type of apparatus homogenization is brought about by setting one of the parts of the valve rotating at high speed.

In all these cases two considerations are in the foreground: The opening or openings through which the liquid flows are made very narrow and long in order that homogenization takes place through the action'of the greatest possible friction between the liquid and the walls. Further any fluctuation of pressure is avoided as far as possible by the arrangement of resilient parts which react as quickly as possible on any fluctuation of pressure.

The'homogenization apparatus based on these principles are of complicated design and of little mechanical reliability and therefore. accompanied by quite a number of inconveniences. Thus the cone valve must be fitted in its seat with the means of a spring, and

greatest care and frequently polished. Since the degree of homogenization depends on the pressure, it is necessary to first carefully adjust the pressure when starting work, for instance by during operation the pressure must "be kept "under constant control. The necessity of usingmanometersforms another drawback, since they are not able to with-' stand the high and fluctuating Pressure so that frequent breakage and other disturbances will occur.

In the means according to the present inventio'n gall these drawbacks are avoided.

' The invention is based on the insight, gained after much experimenting, that the two main considerations mentioned above are not correct.

It h'as been found "altogether unnecessary, in

the liquid with considerable frictionthrough between two surfaces arranged in close juxtaposition and it is unnecessary also to avoid fluctuations of pressure. On the otherhand it appears to be particularly important to utilize the available energy for imparting to'the liquid the most inhomogeneous distribution of velocity, in order to obtain an amount of internal friction as reat as possible. I

ln accordance therewith this invention consists therein thatliquids are homogenized by forcing an. enclosed jet of the liquid under treatment under high axial pressure and at a gradually rising speed, but with no external friction, to suddenly twice reverse its direction of flow, while. relieving the liquid, during and after the reversals of the pressure acting thereon. Since no permanent pressure is required, this invention may be carried out with the aid of a wide nozzle which does not comprise any movable or resilient part. 2

Since the process of homogenization is concentrated in a very small space, a rise of temperature will take place at this point which in many cases promotes homogenization.

The effect resulting from the rise'in temperature may be increased further by taking care that the heat is abducted as little as possible, for instance by insulating the outer wall of the nozzle and/or covering it with a metal of heat reflecting capacity.

In the drawing afiixed to this specification and forming part thereof a device embodying this invention is illustrated diagrammatically by way of example in axial section.

Referring to the drawing, K is a nozzle body and M is a conduit of frusto-conical axial section formed in this body, this conduit tapering evenly from the intake end A toward the exhaust end B. At the exhaust end the conduit widens abruptly into a coaxially extending conduit P of substantially constant, relatively much larger diameter, in which is coaxially flxed a baiile body G of materially lesser diameter which presents to the exhaust opening of the conical conduit an immovable baflle surface. A counter-bathe D surrounds the exhaust opening 13. A plate R formed with large openings E holds the baiiie body G in position in the conduit P.

The liquid, such as for instance milk, is sup.- plied to this nozzle at A under a high pressure, for instance 200 atmospheres. The exhaust opening 13 may have a diameter of for instance 1 to mms., according to the capacity and to the desired degree of homogenization. With a predetermined degree of homogenization in apparatus serving to homogenize 500 or 5000 liters per hour the diameter of the opening B will be for instance 1.6 and 5 mms., respectively. The funnel-shaped conduit serves for raising the velocity of flow of the liquid with the least possible external friction and therefore the least possible expenditure of energy. For the same reason the wall of the inlet is smoothly polished. When the liquid has passed through the opening, it is already homogenized to a certain degree by the great increase of velocity. The degree of homogenization is now increased still further by the stationary baflie surface 0 which causes the turbulence of the liquid to increase. This turbulence is increased further by making the baflle surface and the counter-bailie surface D concave. The liquid flowing through M in axial direction is dispersed on meeting the baflle surface C and is forced to change its direction of flow, being deflected toward the counter-baflle surface D and by its impact on this surface being forced to once more change its direction so that it now flows again in its initial direction. .The liquid escapes from the nozzle through the large perforations E.

All parts of this nozzle are solidly mounted in this relative position. The lack of movable parts renders the operation of this nozzle particularly easy and convenient.

When the pump supplying the liquid at A is operated at a predetermined number of revolutions, the eflect of homogenization will be constant. The device, once set operating, does not require any supervision, and pressure gauges may be dispensed with altogether.

Another important advantage of this invention consists therein that the consumption of energy is considerably lower than in apparatus according to the prior art mentioned above, or inversely at an equal consumption of energy the degree of homogenization is higherr In the nozzle according to this invention the temperature of the liquidrises whereby homogenization is promoted still further. Therefore the heat is not abducted, but the outer wall of the nozzle is heat-insulated by imparting to it a high reflecting power or enveloping itin material of low heat conductivity.

Various changes may be made in the details disclosed in'the foregoing specification without departing from the invention or sacrificing the advantages thereof.

I claim:

1. Liquid homogenizing device comprising a nozzle body traversed by a conduit of frustoconical axial section'tapering evenly from the intake end towards the exhaust end and abruptly widening into a co-axially extending conduit of substantially constant, relatively. large diameter, a bailie body of materially lesser diameter removably flxed in the widened part of said conduit'and presenting to the exhaust end of the conical parts of said conduit an immovable bailie surface, and

a counter-bailie surface surrounding the exhaust end of the conical part of said contact.

2. The device of claim 1, in which the counterbame surface is a concave surface.

3. The device of claim 1, in which the bane 

